Sewing machine



Sept. 7, 1948. c. c. SMITH SEWING MACHINE Filed Sept. 7, 1946 5 Sheets-Sheet 1 Sept. 7, 1.948.

c. sMrrH SEWING MACHINE 5 Sheets-Sheet 2 Filed Sept. '7. 1946 INVENToR. A CLARE/vas' 6.* JM/rw I I I I I I I l I HIIIIIIIIIIlmIIIIIIIIiHIII I lmu I III III I1 Il IIEIIII IIIIIII !A H mSw vl B tu r I la y ATTORNEY Sept. 7. 1948. c. c. SMITH 2,449,018

' SEWING MACHINE l Filed Sept. 7. 1946 5 Sheets-Sheet 3 1 8/8 74 72 V69 INVENTOR.

Sept. 7, 1948."

c. C'. sMrrH 2,449,018 SEWING MACHIN'FJ Filed sept. 7, 194e 5 sheets-sheet 4 `T l l I9 l ff lo INVENTORQ C24/favos 6.' 5M/2W ATTOHSEY Patented Sept. 7, 1948 "SEWING MACHINE Clarencer C. Smith, Chicago, Ill., assignor .to `Union ySpecial Machine Company, Chicago, Ill.,

Va. corporation of Illinois vApplication September 7, 1946, Serial No. 695,487

6 Claims. f l The present invention relatesto sewing machines and` more particularly, to the feed mech- :anism for such machines." It is an .object -of the `invention to provide means for .regulating the Aextent of feeding motion ofthe feed mechanism of a'sewing machine.

Av further object of the invention is to provide a simple, easily operated and accurate feed reguflating means for sewing machines.

`A further .object of the 'present yinvention is to provide a feed 'regulating means which 'is sub- -stantiallyvibrationless.in operation andzthus .is

@particularly adapted for use .in high-speed sewing machines.

It is .a further object of the present invention `to provide 'feedfregulating means of the'character `described above which vis exceedingly durable and which includes provision for .simple Vcompensa- 'tion of suchwear as may occur.'

Other and further objectsof the .present invention will in part be obvious andiwillin .part'become apparent upon a consideration -of the following .description of a preferred .but1not necessarily-the only embodiment of the-invention taken in connection with the drawings accompanying andforming a part of the present specification.

. In the drawings:

` Fig. 1 -is a vertical sectionof a sewing machine yto which the -present 'invention maybe adapted;

Fig. 2 is a horizontal section-along' theline II-l1 in Fig. `1;

Fig. 3 is `an end elevationalview partly insecrtion of the machine as-viewed from'the llei'tzin lFig. `1; Fig. 4 is an end elevational View,v from the right in Fig. 1, with portions broken'fawayto illustrate interior parts of the machine;

Fig. V5 is a vertical sectionalviewftaken on lthe line V-V in Fig. 2; i

"VIL-VII in Fig. 6; and

Fig. 8 is an enlarged, detailed sectional viewfof 'certain parts of the machine.

f Referringnow to the drawings, the present `in vention has Ibeen illustrated as embodied in a `lockstitch sewing machine of known type.: It will be understood, however, that the present invention isadaptable tofisubst'antially 'any' lform. `of

:sewing machine in which a feed-dog is used. `In vFig. 1 the machine 'shown includes a hollow base `having a removablelbottomiwail vHl and sealing f-'gasket Hand a topV wall or vclothplate l2. :.'In

Fig. .-2 it will be `observedtl'iat the base is Aprovided with front and rear walls i4 and.v I6. The 4base also includes a right end wall t8 and a left l.end Wall 19, these walls being identified as Iright and vleft merely -for the purpose of orientation. The hollow base just described containscertain elements of the sewing mechanism and as shown in Fig. l, contains Vupper and lower .oil.:sumps20 yand 2l, respectively. t The machine includes a hollow standardt2`2 which communicates at its lower end witlithe -hollow base just described and which may `have integrally formed therewith=ahollow arm. .24 terminating in a head 26. y The: main `operating shaft of the machine is shown at 28 in;Fig. 1.` This shaft extends through the. arm `24 and-.carries atlits-outer end a comrbined yhand and belt Wheel 30 by which the ma- Y.chine may :be-operated either manually orgunder qpower. Thehead `26 -has mounted therein Ifor vertical reciprocation a needlefbar 3]2 carried in bushings1 33 :and 34 within thehead. 25.- At`.rits .lowerend the needle bar may be :tted witha needle36. The yshaft 28iha-s securedthereto Within thehead 2B a crank-head` 38 4whichis connected A.through a link` 40 to the-needle bar 32 to impart Vthereto `one completereciprocation upon each revolution ofthe main driving shaft 28.

:l `The Ishaft- 28 has fixed thereto within the hollow standard 22 va gear 42 meshing with anv idler gear 44 carried upon a suitable shaft 45 rotatably mounted; inbushings-\1;irovided in `the hollow 'istandard .422. `The idler gear 44 meshes with a `gear 4Bi'xed to a' shaft 48 Aextendinglongitufidinally of` the `hollow base.` In the particular fm'achine chosen-for illustration herein the gears :46 and 42 'are vojthesame diameter wherebythe shaft 48 `is driven at fthe Vsame angular :speedas the shaft :28. The shaft 48 is carriedfinfsuitable .bearings 49; 5Daand .5| `mounted in suitable web :or:lugzformations in the base casting. 'The shaft 248 has xed thereto a, gear 5'2 `which meshes with afgear 54 fixed .to fafhook shaft lindicated generallyat '56'. At itslefthand end, as shown in-Fig.1, the hook `shaft -56acarries a Arotary vhook 58;v The ,hook'158 has been omitted fromFig. 2. It :will be Lunderstood that theloop-taking mechanism of the machine .1m-ar7 be of any'suit'able form, the frotary f-hookY :shown in the present, embodiment y,being `lnex-'elyra-n illustration. :In the present embodi- Y.nient)ther-ratiobetween'gears 52-and 541s such ',ithatathe rotary-hook .is driven at twice the` angular speedlof the shaft 48. M

Referring next to Fig. .3, thefeed mechanism of the machinel-includes-:a feed-dog theteeth 3 of which work through suitable slots (not shown) in a throat plate 62 to cooperate with the usual presser foot 64 in feeding the work through the machine. The feed-dog 80 is adjustably secured as by a screw and slot arrangement 66, 61 to a carrier or feed bar 68 and may -be vertically adjusted with respect thereto by a screw 68. The carrier 68 has a cylindrical extension 10 passing through a clearance opening 12 in a longitudinal offset portion 14 of the left end Wall I9 of the base. The carrier extension is secured in a socket member 16 as by set screws 18 (see Fig.v A2).

The socket member 16 has a transverse boss 80 which is freely rotatable upon a pin 82 extending between a pair of arms `84 of a feed-rocker l'86.

The rocker 85 is pivoted upon a longitudinally extending shaft 88 (see Fig. 3) which extendsloetween bushings 90 and 9|, respectively, in the end wall I9 and a laterally offset portion 82 'of the rear wall |6. Preferably the bushings and the shaft 88 are held against movement as by set screws S3.

Referring now to Fig. 5, the feed-rocker 86 also includes a pair of arms 94 rotatably carrying a pin 96 to which a hub 9B is secured as by a set screw 91. f

Referring again to Fig. 2, it will be observed that the hub 98 carries at right angles thereto a tubular member |00 which receives a plunger |02 integral with part of an eccentric strap |04 encompassing an eccentric or crank |06 (see Fig. 8) formed on the shaft 4B. The tubular member |00 and plunger |02 comprise a telescopic pitman which serves to connect the feed-rocker 86 with the crank |06. Inasmuch as the hub 88 and pin 96 are free to pivot on the feed-rocker, it will be apparent that the mechanism, as so far described, will not be effective to produce rocking of the feed-rocker 86 because the pitman |00, |02 will merely telescope while freely swinging about the pin 96. In the present invention the motion of the telescopic pitman |00, |02 is modified by an exceedingly simple mechanical arrangement which may be readily adjusted to vary the extent of movement of the feedrocker from substantially Zero to an extent adequate for the formation of the longest stitch which it may be desired to form on any particular machine. It is this latter mechanism to which the present invention is particularly directed.

The mechanism for regulating the movement of the feed-rocker 86 includes a longitudinally extending regulating shaft |08 journalled in bearings located respectively in a wall portion ||0 at the right end 'of the base and a'lugY H2 formed on the rear wall of the base. At its right end the shaft |08 carries an arm ||4 which may be adjustably secured to shaft |08 as by a set screw ||6 (see Fig. 4). A torsion spring ||B is shown in Figs. 2 and 4 and is so arranged as to bear against a lateral extension |20 of the arm ||4 and to tend to rotate the arm ||4 and shaft |08 in a counterclockwise direction as viewed in Fig. 4. A longitudinally adjustable rod |22 extends generally transversely of the right end of the base. One end of rod |22 abuts against the arm I4. At its other end the rod |22 is provided with a threaded portion |24 received in a threaded b'ore |26 in the base casting. A suitably graduated regulating knob |28 is also fixed for rotation with the rod |22 whereby the rod |22 may be projected or retractedwith respect to the arm ||4. Thus, adjustment of the rod |22 by manual turning of the knob |28 will determine-the an- 4 gular position of the regulating shaft |00 under influence of the torsion spring ||8,

Referring to Fig. 2 and Fig. 6, the shaft |08 has fixed at its forward end a generally cylindrical collar |30. The collar |30 may be secured to the shaft |08 by set screws |32 or the like. The collar |30 has formed in the lefthand face thereof,` as viewed in Fig. 2 or Fig. 6, a diametrically disposed slot |34 which serves as a slidevway for a block |36 (see Fig. '1). The block |36 is freely rotatable upon a reduced portion |38 f of I:astud |40 secured to the tubular member |00 of the telescopic pitman. It will be apparent -that rotation of the regulating shaft |08, as by turning the knob |28, will result in changing the angular position of the slot or slideway |34 relative tothe longitudinal axis of the telescopic pitman` |00, |02. If the regulating shaft is adjustedto such position that the slot |34 is substantially normal to the axis of the pitman when the latter is in its intermediate position, there will be substantially no rocking movement imparted to the feed-rocker 06 when the machine is operated. In such adjusted position the block |36 will move up and down in the slot |34 and thus in a path which is tangent to the arc in which the block |36 would move if unconned. Since the length of the arc is very short compared to the radius thereof, the confining of the block |36 to a tangential path will cause only a very slight rocking of the feed-rocker 86. This very slight movement may be ignored for practical purposes and the'feed-rocker 80 may be considered to be substantially stationary. However, if the angular position of the slot |34 is changed even a very small amount, a relatively great modification of pitman movement will occur. Thus the knob |28 may be rotated to vary the angular position of slot |34 and thus to vary the amplitude and relative direction of rocking of the feed-rocker 86.

In the machine chosen for illustration herein the feed-rocker motion may be so varied by adjustment of the slot |34 from normal to approximately twenty-one'degrees on either side of normal as to produce effective feed-dog motion of from substantially zero to approximately five thirty seconds of an inch in either direction. While it will be recognized that such a range of adjustment is adequate for the great majority of sewing machines, such range may be Very much increased if so desiredby tilting the slot v|34 througha greater range. It has been found that the slot |34 may be tilted in either direction as much as thirty degrees without causing rough or irregular movement cr undue wear.

It will be understood that adjustment of the slot |34 to an angular position other than generally normal to the longitudinal axis of the telescopic pitman |00, |02 will result in confinement ofthe block |36 to a vpath not tangential to `its normal arc of movement and that the effect will beto draw the tubular telescopic member l|00 forwardly or project it rearwardly as viewed in Figs. 2 and 6, dependent upon the direction in which the slot |34 has been tilted. Within the limits necessary to secure adequate feed-dog regulation the modification of pitman movement is effected without establishing angular relationships between the parts which might result in undue strain or rapid Wear. The slotted collar I |30 may be made of hardened metal and in such event may be expected to have a life fully comparable to most of the other parts ofthe machine. Preferably the'block. |36 is `formedasa operating shaft, a feed-rocker for imparting movement to said feed-dog, an eccentric on said operating shaft, a pitman connecting said eccentric with said feed-rocker, said pitman'including telescoping members having afree-sliding connection one with the other and one of said telescoping members being freely vpivoted to said feed-rocker, a slotted guiding member, a regulating shaft rotatably mounted in said frame and having said slotted guiding member secured thereto in a position wherein the longitudinal axis of the slot in said slotted guiding member extends transversely of the longitudinal axis of said regulating shaft, a block freely pivoted on one of said telescoping members, said block having a plurality of pairs of opposed equally spaced parallel faces the spacing between the faces of each of said pairs being such that the faces in any pair may be arranged in sliding relationship respectively with opposed walls of the slot in said slotted guiding member, said block extending into the slot in said slotted guiding member for sliding motion longitudinally of said slot as an incident to swinging of said telescopic pitman whereby to impart endwise motion to the member of said telescopic pitman to which said rectangular block is freely pivoted and thereby to impart an oscillating motion to said feed-rocker to variable extents dependent upon the angular relationship between the longitudinal axis of the slot in said slotted guiding member and the longitudinal axis of said telescopic pitman, a lever secured to said regulating shaft, and means accessible from the outside ofsaid frame for engaging and moving said lever to vary the position of the slot in said slotted guiding member to regulate the extent of oscillating motion imparted to-said feed-rocker.

5. In a sewing machinea frame, a feed-dog, an operating shaft, a feed-rocker for imparting movement to said `feed-dog, an eccentric on said operating shaft, a pitman connecting said eccentric with said feed-rocker, saidl pitman including telescoping members havinga free-sliding .con-

nection one with the other and one of said telescoping members being freely pivoted to said feedrocker, a follower projection extending laterallyy from said one telescoping member, a slotted guiding member adapted to receive said follower projection to impart oscillating motion to said feed,- rocker, a` bearing projection extending laterally from said one telescoping member in a direction opposite to said follower projection, and an abutment on said frame positioned to engage said bearing projection.

6. In a sewing machine a frame, a feed-dog, 'an operating shaft, a feed-rocker for imparting movement to said feed-dog, an'eccentric on said operating shaft, a pitman connecting said eccentric with said feed-rocker, said pitman including telescoping members having a free-sliding connection one with the other and one of said telescoping members being freely pivoted to said feedrocker, a follower projection extending laterally from said one telescoping member, a slotted guiding member adapted to receive said follower projection to impart oscillating motion to said feedrocker, a bearing projection extending laterally from said one telescoping member in a direction opposite to said follower projection, an abutment on said frame having a bearing surface aligned with said bearing projection, and means for adjustably securing said abutment in position to cooperate with said bearing projection to guide said one telescoping-member.

CLARENCE C. SMITH.

REFERENCES CITED The folloi'vingreferences' are of rcord in the file of this patent:

UNITED STATES PATENTS Number Hohmann Jan. 24, 1939 

